drm/panel: Make of_drm_find_panel() return an ERR_PTR() instead of NULL
Right now, the DRM panel logic returns NULL when a panel pointing to
the passed OF node is not present in the list of registered panels.
Most drivers interpret this NULL value as -EPROBE_DEFER, but we are
about to modify the semantic of of_drm_find_panel() and let the
framework return -ENODEV when the device node we're pointing to has
a status property that is not equal to "okay" or "ok".
Let's first patch the of_drm_find_panel() implementation to return
ERR_PTR(-EPROBE_DEFER) instead of NULL and patch all callers to replace
the '!panel' check by an 'IS_ERR(panel)' one.
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180509130042.9435-2-boris.brezillon@bootlin.com
diff --git a/drivers/gpu/drm/bridge/cdns-dsi.c b/drivers/gpu/drm/bridge/cdns-dsi.c
index f2d43f2..ce9496d 100644
--- a/drivers/gpu/drm/bridge/cdns-dsi.c
+++ b/drivers/gpu/drm/bridge/cdns-dsi.c
@@ -1152,7 +1152,7 @@
np = of_node_get(dev->dev.of_node);
panel = of_drm_find_panel(np);
- if (panel) {
+ if (!IS_ERR(panel)) {
bridge = drm_panel_bridge_add(panel, DRM_MODE_CONNECTOR_DSI);
} else {
bridge = of_drm_find_bridge(dev->dev.of_node);